Nineteen new species of a tree-living praying mantis family have been discovered, tripling the group’s diversity at a stroke.

The bark mantises (Liturgusa Saussure) from Central and South America were found in tropical forests and among specimens kept in museums.

Many of the newly described species are known only from a few specimens collected before 1950 from locations now heavily impacted by agriculture or urban development.

“Based on this study, we can predict that mantis groups with similar habitat specialisation in Africa, Asia and Australia will also be far more diverse than what is currently known,” said Dr Gavin Svenson, curator of invertebrate zoology at the Cleveland Museum of Natural History in the US.

“Many of these groups have never been studied other than by the scientists that originally described some of the species, which in some cases is more than 100 years ago. This is exciting because enormous potential exists for advancing our understanding of praying mantis diversity just by looking within our existing museum collections and conducting a few field expeditions.”

Dr Svenson searched for the insects in eight countries in Central and South America, and studied hundreds of specimens from 25 museums in North America, South America and Europe.

Bark mantises are fast runners that live on the trunks and branches of trees. Contrary to the common perception of mantises being slow, methodical ambush experts, the insects are active hunters that pursue their prey. Also unlike some other mantis species, they are not believed to engage in cannibalism.

They are highly camouflaged and evade predators by running to the opposite side of their tree – a tactic also adopted by many tree-dwelling lizards.

“This is an amazing behaviour for an insect because it shows that they are not only relying on camouflage like most insects but are constantly monitoring their environment and taking action to run and hide,” said Dr Svenson. “In addition, some species leap off the tree trunk to avoid capture and play dead after fluttering down to the forest floor since none of the species are strong fliers.”